Automobile control.



M g ISAAC FEAKER: f i 'iw fl- JfgLaw;

. I I. P. BAKER.

Patented Nov. 26, 1912.

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M/PTJVESEEE: [NS/ENTER ATTY I. F. BAKER.

AUTOMOBILE CONTROL.

urmou'um FILED JUNE 7, 1909.

1,045,496; Patented Nov. 26, 1912.

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aw BY .Y I TT UNITED STATES PATENT OFFICE.

ISAAC F. BAKER, OF EAST ORANGE, NEW JERSEY, ASSIGNOR, BY MESNE ASSIGNMENTS, TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

AUTOMOBILE CONTROL.

1 ,oesaoe.

To all whom it may concern:

Be it known that I, Issac F. BAKER, a citizen of the United States, residing at East Orange, county of Essex, State of New J ersey, have invented certain new and useful Improvements in Automobile Controls, of which the following is a specification.

My invention relates to the control of self'propelled vehicles or automobiles of the type in which a plurality of electric motors are employed. and connected to different driving wheels, and in which current for the motors is tarnished by a generator driven by a prime mover, such as a gasolene engine on the vehicle. In. such automobiles it has heretofore been the usual practice to have the motors connected permanently in parallel. because it they are in series and one driving wheel happens to be on a slippery part of the road that wheel will. spin around and the motor driving it will. take all the voltage, while the other driving wheel stands still and the vehicle will not start. A convenient method of controlling the motors consists in varying the generator voltage, but with the motors connected permanently in parallel the conditions of operation are severe for the generator, on account of the fa ct that when the largest current is drawn from the generator, as in starting, the field is weakest, which makes commutation very diiiicult.

The object of my invention is to obviate this difiiculty.

.My invention consists in providing means for deriving from the generator a neutral point with respect to the terminal voltage of the generator and connecting the motors in series to the generatt'ir terminals but with the middle point oi": the motor circuit connectcd to the neutral point of the generator. By means of this arrangement equal voltages are maintained on both motors, so that the slipping of one wheel is avoided, while at the same time since the motors are in series-at starting the armature current of the generator is less and the field stronger than with the usual control.

My invention will best be understood by Specification of Letters Patent.

Patented Nov. 26, 1912.

Application filed June 7,1909. Serial No. 500,684.

reference to the accompanying drawings, in Wl11Cl1- Figure 1 shows a plan view of the frame. of an automobile, of the type to which my with current from the generator 13 and connected to different driving wheels D D.

As shown in Fig. 2, the generator B in addition to the main brushes Z), I) has an auxiliary brush 7) placed intermediate the main brushes and, consequently, at a poten* tial neutral, with respe t to that of the main brushes. The generator is provided with a shunt winding 5 and may be provided with a series winding 7). C represents the armature and c the field of one motor, and G the armature and 0 the field of the other motor. E represents the controlling swit' which has six positions. indicated by dot lines 1 to G. for forward movement, and six positions, indicated by 1 to (3' for reverse. F represents a resistance adapted for connection in series with the shunt winding Z2 to-vary the generator voltage.

lVhen the controller E is moved into the first forward position, indicated by dotted line 1, the upper brush 6 of the generator is connected through the upper series field Z2 to the motor field c. The circuit contimies through the motor armature C motor armature C, motor field c. lowen series field b to lower brush 7). Both motors are thus connected in series acrc'ssthe generator terminals, while the middle point of the motor circuit, that is, the point of connection between the two motor arinatures. is also connected to generator brush k). These connections as just t need are shown in Fig. 8. It will be seen that. while the two motors are in series, the voltages of the two motors are maintained equal by the connection to the neutral brush 6. It will further be noted that each armature has the field of the Y ator voltage is at its owest value.

other motor connected directly in series with it, this connection serving to equalize the,

' 'fourth. position the'resistanoe'Fis again cut into 'circuit iso as to weaken the neratorfield, the connection to the neutra brush 6' is broken, and the ,two motors are connected in parallel/across the generator terminalsas shown in Fig. 4. In moving to the fifth and sixth posiiifi, the switch E again gradually cuts out 1" ance F so as again to increase the generator voltage. Inmcying through its reverse positions the same connections are established except that the armature of one motor and the field ofthe other are reversed, with respect to the other half of the motor circuit, so that the torque of both motors is reversed. V

Instead of an auxiliarybrush placed on the commutator between the main brushes, other arrangements for deriving from the generator a neutral point with respect to the terminal voltage may be employed. For

instance, in Fig. 5. I have diagrammatically "illustrated one well-known arrangement for this purpose consisting of a choke coil or reactance G connected across diametrically opposite points on the armature winding with its central point connected to a collector ring ,9 on which bears a brush Z) which takes the place of the commutator brush 5' of Fig. 3.

I do not desire to limit myself to the particular arrangement shown, but aim in the appended claims to cover all modifications Zvhich come within the scope of my invenion.

What I claim as new and desire to secure by Letters Patent of the United States. is,

1. In a self-propelled vehicle. a pair of electric motors connected to diilercnt driving wheels of the vehicle. a prime mover. an electric generator driven thereby. means for deriving from said generator a neutral point with respect to the terminal voltage of the generator, means for connecting the motors means for varying in series across the terminals of said generator and connecting the middle point of the motor circuit to said neutral point. and the field strength of said generator.

2. In a self propelled vehicle, a pair of electric motors connected to different driving. wheels of the vehicle, a prime mover, an

ture of one motor and the field of the other in series between one terminal of the gen orator and said neutral point and the armature of the second motor and the field of the first motor in series between said neutral point and the other terminal of the genera tor, and means for varying the field strength of said generator.

-- 3. In a self-propelled vehicle a pair of electric motors connected to difi erent driving wheels oi the vehicle, a prime mover, a variable voltage electric generator driven thereby, means for derivin from said generator a neutral point wit respect'to the terminal voltage of the generator, and a controlling switch having its contacts arranged to connect the motors in series across the generator terminals with the middle point of the motor circuit connected to said neutral point, and subsequently to open the connection to said neutral point, and connect the motors in parallel across the generator terminals.

4. In a self-propelled vehicle, a pair of electric motors connected to different driving wheels of the vehicle, a prime mover, an electric generator driven thereby, means for deriving from said generator a neutral point with respect to the terminal voltage of the generator, and a controlling switch having its contacts arranged in 'one posi tion to connect the motors in series across the generator terminals with the middle point of the motor circuit connected to said neutral point, in a subsequent position to strengthen the enerator field by cutting resistance out of the generator field circuit, in a still subsequent position to open the con: nection to said neutral point, weaken the generator field by cutting resistance into the generator field circuit, and connect the motors in parallel across the generator terminals, and in a still subsequent position again to strengthen the generator field by cutting resistance out of the generator field circuit.

5. In a self-propelled vehicle, a pair of electric motors connected to difierent driving wheels of the vehicle, a prime mover, an electric generator driven thereby, means for deriving from said generator 9. neutral point with respect to the terminal voltage of the generator, and a controlling switch having its contacts arranged in one position to connect the motors in series across the generator terminals with the middle point of the motor circuit connected to said I Copies. this patent may be obtained for neutral point, in a subsequent osition-to strengthen the generator field E resistance out of the generator field circuit, in a still subequcnt position to open the connection t0 said..neutrulf-point, Weakenthe generator field by cutting resistance into the generator field circuit, and connect the motors in parallel across the generator terminals, and in a still subsequent position again to strengthen the generator field by y cutting cutting resistance out of the generator field circuit, each motor armature in each of said connections having the field of the other motor directly in series with it.

In Witness whereof. I have hereunto set- 15 five cents each, by addressing the Commissioner of Patents, Washington, D. 0. 

